CVE-2015-2792 in WPML Plugin
Summary
by MITRE
The WPML plugin before 3.1.9 for WordPress does not properly handle multiple actions in a request, which allows remote attackers to bypass nonce checks and perform arbitrary actions via a request containing an action POST parameter, an action GET parameter, and a valid nonce for the action GET parameter.
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Analysis
by VulDB Data Team • 05/02/2022
The vulnerability identified as CVE-2015-2792 affects the WPML plugin version 3.1.8 and earlier, representing a critical security flaw that undermines the integrity of WordPress site administration. This issue stems from improper handling of multiple actions within a single HTTP request, creating a dangerous condition where attackers can manipulate the plugin's behavior by crafting specific requests containing both POST and GET parameters alongside valid nonces. The flaw exists at the core of the plugin's request processing logic, where it fails to properly validate or prioritize the action parameters, allowing malicious actors to exploit this inconsistency in action handling.
The technical implementation of this vulnerability involves the plugin's failure to correctly process multiple action parameters within a single request context. When a request contains both action POST and action GET parameters, the system does not properly validate which action should take precedence or whether the combination is legitimate. The vulnerability specifically leverages the fact that a valid nonce for the GET action parameter can be used to bypass security controls that should normally prevent unauthorized actions, effectively allowing attackers to execute administrative functions without proper authorization. This represents a classic case of improper input validation and insufficient access control mechanisms, classified under CWE-284 Access Control Issues in the Common Weakness Enumeration catalog.
The operational impact of this vulnerability is severe and far-reaching, as it allows remote attackers to perform arbitrary administrative actions on compromised WordPress sites. Attackers can exploit this weakness to modify content, add or delete users, manipulate site settings, and potentially gain full control over the affected WordPress installation. The vulnerability's exploitability is particularly concerning because it requires no authentication for the initial attack vector, relying instead on the proper manipulation of nonce values and action parameters. This weakness can be leveraged to execute attacks that align with ATT&CK technique T1078 Valid Accounts, as attackers can gain unauthorized access to administrative functions through legitimate nonce validation mechanisms.
The security implications extend beyond immediate administrative compromise, as this vulnerability can serve as a foothold for more extensive attacks within the WordPress ecosystem. Once an attacker successfully exploits this vulnerability, they can establish persistent access, deploy malware, or use the compromised site as a launching point for attacks against other systems. The vulnerability also demonstrates poor secure coding practices in handling HTTP requests and parameter validation, highlighting the importance of proper request sanitization and action parameter prioritization. Organizations should immediately update to WPML version 3.1.9 or later, which addresses this vulnerability through improved parameter handling and enhanced nonce validation mechanisms. Additionally, implementing additional security measures such as web application firewalls, monitoring for suspicious parameter combinations, and regular security audits can help mitigate the risk of exploitation. The vulnerability serves as a reminder of the critical importance of proper input validation and access control implementation in web applications, particularly in plugins that handle administrative functions and user privileges.